Information basic to understanding retinal disorders at a cellular level is acquired from experiments which combine the technologies of neuropharmacology, intracellular electrophysiology, and cell biology, including cell culture. The actions and interactions of neurotransmitters, neuromodulators, hormones and selected drugs on retinal neurons are examined. The specificity and stability of synapses made by embryonic retinal neurons under various controlled conditions of culture are studied quantitatively.